Importance of the buffer zone of the water intake for the maintenance of agrosystem phytodiversity.
A change of the agricultural policy in Poland after 1990 caused significant changes in the structures of the agricultural landscape functioning in the area of West Pomerania (Pomorze Zachodnie). The field fragments, which had been in a form of barren land in the protective zone of Miedwie Lake for 30 years, were chosen for the detailed phytosociological studies. The aim of the current study was the analysis of anthropogenic impacts on flora in the surveyed terrain. In the studied area, the values of the synanthropization indices of the flora were as follows: synanthropization - 2.58, apophytisation - 2.0, anthropophytisation - 0.56, archaeophytisation - 0.38, kenophytisation - 0.16, and fluctuation changes in the flora - 0.04. It is assumed that the larger the share of nonsynanthropic species, the larger the naturalness of the flora in these biotopes. The large values for the apophytisation index showed degradation in natural habitats A large share of anthropophytes indicates dominance of the processes of a decline in native species in a given biotope, which means that there are disturbances of the ecological balance of a given ecosystem. The 30 year cessation of agricultural use around the lake resulted in the improvement of the chemical state of waters. A significant role in stopping water runoff played dense sodification of the surveyed area. The state of the flora found in this area was influenced by both natural and anthropogenic factors. This is proved by the dominance of synanthropic over nonsynanthropic, and spontaneophytes over anthropophytes species.